2645519781 has 8 divisors (see below), whose sum is σ = 3575680000. Its totient is φ = 1739519712.

The previous prime is 2645519771. The next prime is 2645519783. The reversal of 2645519781 is 1879155462.

It is a happy number.

It is a sphenic number, since it is the product of 3 distinct primes.

It is not a de Polignac number, because 2645519781 - 2¹¹ = 2645517733 is a prime.

It is a super-2 number, since 2×2645519781² = 13997549823324575922, which contains 22 as substring.

It is a Duffinian number.

It is a self number, because there is not a number n which added to its sum of digits gives 2645519781.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (2645519783) by changing a digit.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 6039781 + ... + 6040218.

It is an arithmetic number, because the mean of its divisors is an integer number (446960000).

Almost surely, 2^2645519781 is an apocalyptic number.

It is an amenable number.

2645519781 is a deficient number, since it is larger than the sum of its proper divisors (930160219).

2645519781 is a wasteful number, since it uses less digits than its factorization.

2645519781 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 12080075.

The product of its digits is 604800, while the sum is 48.

The square root of 2645519781 is about 51434.6165631669. The cubic root of 2645519781 is about 1383.0472083636.

The spelling of 2645519781 in words is "two billion, six hundred forty-five million, five hundred nineteen thousand, seven hundred eighty-one".